1. Technical Field
The present invention relates to a cooling method and device for a notebook personal computer. More particularly, the invention relates to a method and a device for forced cooling of a heat generating component which generates a significant amount of heat.
2. Description of the Related Art
High performance notebook personal computers (hereinafter referred to as PCs) require high performance central processing units (hereinafter referred to as a CPUs). However, high performance electronic components such as CPUs generate a significant amount of heat during operation, which degrades its processing speeds and performance. For this reason, high temperature, heat generating components such as CPUs have been provided with cooling means.
Means for cooling a high-temperature heat generating component is designed in response to a temperature generated by the component. Specifically, when the heat generating component generates extremely low heat, it is air-cooled without using any cooling component. When the heat generating component generates relatively low heat, it is air-cooled by using a heat sink or a heat pipe. Alternatively, when the heat generating component generates a significant amount of heat, it is forcibly cooled by using a fan motor, or by using both a Peltier device and a fan motor. However, in today""s high performance notebook PCs, it is impossible to air-cool a heat generating component that generates a large amount of heat. Therefore, such heat generating components are forcibly cooled in almost all high-performance notebook PCs.
One example of a method of forced cooling of a heat generating component is shown in FIG. 8 and FIG. 9. In FIG. 8, a heat sink 3 with fins and the like is stacked on a heat generating component 2 such as a CPU mounted on a substrate 1, and the component 2 is forcibly cooled by a fan motor 4. In FIG. 9, a heat sink 3 with fins and the like is stacked on a heat generating component 2 such as a CPU mounted on the substrate 1 through a Peltier device 5, and the component 2 is forcibly cooled by a fan motor 4. In FIG. 9, the Peltier device 5 may produce higher heat-radiating effect than in the FIG. 8. Such forced-cooling methods shown in FIG. 8 and FIG. 9 have been adopted in desktop PCs.
However, if the above cooling methods used in desktop PCs is adopted to notebook PCs, the following three serious problems will arise:
1. Height limitations. The height of a notebook PC is required to be as low as possible in terms of portability and operability. Therefore, the height of a notebook PC should not be determined by the design of a cooling device, and as a matter of course, a cooling device should be designed to be lower than the heights of the other functional components. However, since the height of a notebook PC can not be increased any more, no additional space for a cooling device is left in the notebook PC.
2. Power consumed during cooling. A large amount of power is needed to operate a fan motor and a Peltier device, and the power applied to the fan motor and the Peltier device is obtained from the power source for activating the other functional components. For this reason, when a battery is used, continuous operation period of power is dramatically shortened.
3. When a Peltier device is used, it is necessary to supply power to the Peltier device and the fan motor continuously. In other words, if the Peltier device is not operated, it gives a significant amount of heat resistance, and thus it does not function as a cooling device at all. Therefore, when the battery is used, continuous operation period of power is dramatically shortened.
In the prior art, Japanese Patent Publication No. 10-107469 discloses a cooling device comprising a heat conductive member, one end of which is connected to a heat generating component; a heat radiating member connected to the other end of the heat conductive member; and air guiding means for transmitting air to the surroundings of the heat radiating member. It discloses that the heat conductive member is a heat pipe, the heat radiating member comprises fins, and the air guiding means is equipped with a fan, however, it does not mention or indicate that the cooling device may have other structures.
In the future, faster and higher performance CPU will be mounted on a notebook PC which will generate more heat during operation. Since the above-mentioned conventional cooling device lacks ability of cooling a high temperature heat generating component or reaches to the upper limit of its height, there is a need to develop new and improved cooling devices.
A cooling method and device for a notebook PC uses the following steps: transferring a portion of heat generated by a heat generating component of a notebook PC to a position different from the position of the heat generating component by heat conduction; forcibly transferring at least a portion of the rest of the heat generated by the heat generating component to a position different from the position of the heat generating component; and forced cooling of the transferred heat. Other steps of the cooling method of the present invention include: transferring heat generated by a heat generating component of a notebook PC to a position different from the position of the heat generating component; cooling the transferred heat by using thermomodule device; and cooling a higher temperature side of the thermomodule device by air flow. In this cooling method, the heat generated by the heat generating component is forcibly cooled in a position different from the position of the heat generating component disposed to a notebook PC. As the way of transferring heat generated by the heat generating component, thermal conduction by a heat sink or forced heat transfer by a heat pipe, a thermomodule device and/or a circulating liquid such as water may be used. Preferably, the transferred heat is absorbed by the thermomodule device and is ejected to the outside by air flow.
The cooling device of the present invention comprises: a heat sink for thermally conducting a portion of the heat generated by the heat generating component of a notebook PC to a position different from the position of the heat generating component; heat transferring means of forcibly transferring at least a portion of the rest of the heat generated by the heat generating component to a position different from the position of the heat generating component; and heat radiating means for forcibly radiating the transferred heat from the heat transferring means. The heat transferring means may comprise a heat pipe, a thermomodule device such as a Peltier device, and/or a cooler comprised of a tube through which coolant is circulated. The forced heat radiating means may comprise a fan or blower for dissipating heat of the heat transferring means to the outside by applying air blow and air suction. In this cooling device, the heat generated by the heat generating component can be transferred to a position different from the position of the heat generating component and then cooled powerfully in that position. Therefore, the height of a notebook PC ( i.e. the thickness of a notebook PC) is not increased, but the ability to radiate heat can be dramatically enhanced. Furthermore, since a thermomodule device and/or an air blower is controlled on the basis of a temperature of the heat generating component, it is possible to self-control the cooling ability and to minimize the power consumption.
An object of the present invention is to efficiently cool a high temperature heat generating component such as a CPU without increasing the height of a personal computer.
Another object of the present invention is to efficiently cool a heat generating component while power consumption for a cooling device is saved.
An object of the present invention is to efficiently cool a high-temperature heat generating component such as a CPU without increasing height of a personal computer.
The foregoing and other objects and advantages of the present invention will be apparent to those skilled in the art, in view of the following detailed description of the preferred embodiment of the present invention, taken in conjunction with the appended claims and the accompanying drawings.